In IEEE 802.11aj specifications, the transmission can be in 540 MHz channel or in 1080 MHz channel, and there are three PHY types including control (CTRL) PHY, single carrier (SC) PHY, and orthogonal frequency-division multiplexing (OFDM) PHY. It is desirable to detect the bandwidth before the channel estimation, especially for single carrier packets since there is no other training field that allows updating channel estimation for different bandwidth, and the receiver (RX) can perform channel estimation on only the occupied bandwidth other than the maximum transmission bandwidth. Packet type should be also detected before the channel estimation and PHY header decoding, and in this way the RX will not have to perform the parallel decoding for multiple possible packet formats. In addition, the bandwidth detection should be detected first since the channel estimation relies on the bandwidth information. However, the conventional method is not capable of detecting bandwidth and the packet type of a packet before the channel estimation.